Syntheses, characterizations, and applications of heli-acenes
A method is provided for using twisted acenes, and more particularly to configurationally stable twisted acenes that are imbedded into the structure of [ 7 ]helicene at the fulcrum ring to form useable material structures. The helicene propagates its chiral nature into the acene, while acting as a locking mechanism to thermal racemization. These doubly-helical compounds are part of a new homologous series of polycyclic aromatic hydrocarbons, namely the [ 7 ]helitwistacenes. Such [ 7 ]helitwistacenes have utility as materials suitable for forming a circularly polarized organic light emitting diode (CP-OLED) for direct emission of circularly polarized (CP) light for the fabrication of high efficiency electronic displays.
1. A heli-twisted acene selected from the group consisting of:
wherein n is 1-3, and X is simultaneously CN, Me or Ph.
2. The heli-twisted acene of claim 1 wherein the heli-twisted acene is at least one of a hole transport layer and an emissive layer of a mulit-layer organic light emitting diode (OLED).
3. The heli-twisted acene of claim 2 wherein the OLED is a circularly polarized OLED.
4. The heli-twisted acene of claim 2 wherein the OLED is a biomedical device.
5. The heli-twisted acene of claim 1 wherein the acene core is highly flurorescent.
6. The heli-twisted acene of claim 1 wherein the acene core has an end to end twist of any of 30°, 60°, and 144°.
7. The heli-twisted acene of claim 1 wherein the acene core has a specific rotation [∝] n 35 32 7400°.
8. The heli-twisted acene of claim 2 wherein the acene core is longitudinally twisted.
9. The heli-twisted acene of claim 2 wherein the heli-twisted acene is a carbocyclic heli-acene.
10. The heli-twisted acene of claim 1 wherein X in every instance is cyano.
11. The heli-twisted acene of claim 1 wherein X in every instance is methyl.
12. The heli-twisted acene of claim 1 wherein X in every instance is phenyl.
13. A process for synthesizing the heli-twisted acene of claim 2 , the process comprising:
performing a bis-Wittig reaction with a 2,8-dibromophenanthrene-5,6-dione to form an intermediate; and
then reacting the intermediate with styene in the presence of a Pd catalysis to synthesize the heli-twisted acene.